Wireless Local Area Network (WLAN) equipment continues to be used as a solution for many different data connectivity applications. WLANs are now viewed as an ideal solution for providing access to wireless equipped personal computers within home networks, mobile access to laptop computers and personal digital assistants (PDAs), as well as providing robust and convenient access in business applications.
Indeed, at the present time many laptop computers are shipped from the factory with WLAN interface cards. Certain microprocessor manufacturers, such as Intel, have also announced intentions to incorporate WLAN capability directly into processor chip platforms. These and other initiatives will continue to drive the integration of WLAN equipment into personal computers of all types.
It is already the case that in many cities, WLAN access equipment operating in accordance with the IEEE 802.11a, 802.11b, and 802.11g standards is in wide use. In these cities one can now find “hot spots” that provide network connectivity. Unfortunately, having tens, if not hundreds, of closely spaced wireless networks using the same radio spectrum means that interference becomes a problem. That is, although the 802.11 standards provide for robust signaling in the form of spread spectrum radio frequency modulation, and using orthogonal frequency division multiplexing over modulated subcarriers, crowding of the radio spectrum still increases noise and therefore decreases performance for all users.
It is recognized that directional antenna arrays can be used to steer radio frequency energy between a transmitter and receiver. This greatly reduces the amount of interference that would otherwise be created for concurrent users of the spectrum. The use of such arrays in wireless subscriber equipment has been described in U.S. Pat. No. 6,100,843 entitled “Adaptive Antenna for Use in Same Frequency Networks”; U.S. Pat. No. 6,400,317 entitled “Methods and Apparatus for Antenna Control in a Communications Network”; and in U.S. Pat. No. 6,473,036 entitled “Method Apparatus for Adapting Antenna Array to Reduce Adaptation Time While Increasing Array Performance”. Each of these patents is assigned to Tantivity Communications, Inc., the assignee of the present application.
However, WLAN signaling has special considerations in that communication is expected to be on a peer-to-peer basis with extremely short packet lengths. It has heretofore been thought quite difficult to require WLAN subscriber equipment to steer an antenna array, to one of many possible candidate angles, during such very short intervals.